Magnetic media with embedded optical servo tracks
View Patent ↗A storage medium is provided that includes a magnetic recording tape having a first side and a second side, and a plurality of optically detectable indicia embedded in a servo layer disposed between the first side and the second side of the tape. The optical reflectivity and/or phase of the indicia are different from the surrounding servo layer, and the indicia are optically accessible from at least one of the first side and the second side of the tape. The servo layer may include an organic material wherein the indicia are created with an infrared or ultra violet light source.
1. A storage medium, comprising:
a magnetic recording tape including a magnetic recording layer and having a major first side and a major second side; and
a plurality of optically detectable indicia embedded in a servo layer, the indicia disposed during formation between the first side and the second side and apart from a surface of the first side and a surface of the second side, wherein the indicia are optically accessible from at least one of the first side and the second side of the tape.
2. The medium of claim 1 , wherein the optical reflectivity of the indicia is different from the surrounding servo layer.
3. The medium of claim 1 , wherein the phase of the indicia is different from the surrounding servo layer.
4. The medium of claim 1 , wherein the servo layer is disposed between a base layer and a magnetic recording layer.
5. The medium of claim 1 , wherein the servo layer includes an organic material.
6. The medium of claim 1 , wherein the servo layer includes carbon.
7. The medium of claim 1 , wherein the indicia are detectable with infrared light.
8. The medium of claim 1 , wherein the indicia are detectable with ultra violet light.
9. The medium of claim 1 , wherein the recording layer is accessible from the first side and wherein the indicia are optically accessible from the first side.
10. The medium of claim 1 , wherein the recording layer is accessible from the first side and wherein the indicia are optically accessible from the second side.
11. The medium of claim 1 , wherein the indicia are optically accessible from the first side and the second side of the tape.
12. The medium of claim 1 , wherein the indicia include a pattern of marks with equal spacing in a linear dimension of the tape.
13. The medium of claim 1 , wherein the indicia include a pattern of marks with equal spacing in a lateral dimension of the tape.
14. A storage medium, comprising:
a magnetic recording tape having a major first side and a major second side;
a magnetic recording layer accessible from the first side of the tape; and
a plurality of optically detectable indicia embedded between the first side and the second side and disposed during formation apart from a surface of the first side and a surface of the second side, wherein the indicia are optically accessible from the first side.
15. The medium of claim 14 , wherein the indicia are formed in a servo layer located between the first side and the second side.
16. The medium of claim 15 , wherein the servo layer is disposed between a base layer and the magnetic recording layer.
17. The medium of claim 15 , wherein the servo layer includes an organic material.
18. The medium of claim 15 , wherein the servo layer includes carbon.
19. The medium of claim 15 , wherein the optical reflectivity of the indicia is different from the surrounding servo layer.
20. The medium of claim 15 , wherein the phase of the indicia is different from the surrounding servo layer.
21. The medium of claim 14 , wherein the indicia are detectable with infrared light.
22. The medium of claim 14 , wherein the indicia are detectable with ultra violet light.
23. The medium of claim 14 , wherein the indicia include a pattern of marks with equal spacing in a linear dimension of the tape.
24. The medium of claim 14 , wherein the indicia include a pattern of marks with equal spacing in a lateral dimension of the tape.
25. A method for forming a servo track, comprising:
forming optical indicia within a magnetic recording tape from a first major side of the tape, wherein
the tape includes the first major side and an opposite second major side, and
the optical indicia are formed below a surface of the first side of the tape and apart from the surface of the first side of the tape.
26. The method of claim 25 , wherein the indicia are optically detectable from at least the first side or the second side.
27. The method of claim 25 , wherein the indicia are optically detectable from the first side and the second side.
28. The method of claim 25 , wherein forming the optical indicia includes using a laser.
29. The method of claim 25 , wherein the optical indicia are formed in a servo layer, wherein the servo layer is disposed between at least a first layer and a second layer.
30. The method of claim 29 , wherein at least one of the first layer and the second layer includes a magnetic recording layer.
31. The method of claim 30 , wherein the optical indicia are optically detectable from the same side as the magnetic recording layer.
32. The method of claim 25 , wherein the optical indicia are formed in a servo layer that includes an organic material.
33. The method of claim 25 , wherein the optical indicia are formed in a servo layer that includes carbon material.
34. The method of claim 25 , wherein the optical indicia are detectable with infrared light.
35. The method of claim 25 , wherein the optical indicia are detectable with ultra violet light.
36. The method of claim 25 , wherein forming the optical indicia includes focusing light to a location below the surface of the first side of the tape.
37. The method of claim 25 , wherein forming the optical indicia includes producing localized heat at a location below the surface of the first side of the tape to modify a portion of the tape.